Figure 2. Oxygenation index (OI) at T1 (operative, after intubation), T3 (40 min after pneumoperitoneum), and postoperative periods T5 (30 min after extubation) and T6 (one day after surgery) in patients treated with protective ventilation (PV) and conventional ventilation (CV). Data are reported as means±SD. *P<0.05 compared with the CV group (t-test).